Interest & Product Logic Specialist · Hamburg ·

Stellenbeschreibung:

We are looking for a specialist who combines financial know-how with strong analytical skills to join our Core Ledger team. Our platform contain core ledger systems both fully developed internaly and developed and delivered by external suppliers. As an Interest & Product Logic Specialist, you will define and document the business rules behind interest, fees, and product configurations, and verify and test that what our internal- and external suppliers deliver matches our requirements and works correctly. A significant part of this role is providing hands‑on internal support to colleagues across the business who have questions about interest, fees, and product behaviour — this is something all specialists in the team spend a lot of time on. Getting this right is essential — it directly affects how accurate and competitive our financial products are. You will join a small, close‑knit team and have a great opportunity to make a direct impact early on and help shape it as it grows.

Key Responsibilities

Define and document detailed requirements for interest calculation logic, accrual rules, and fee structures, to be delivered by external suppliers
Translate financial product requirements from business and product teams into precise specifications for our suppliers
Verify and test the product configuration delivered by suppliers, ensuring it behaves correctly for all financial instruments
Ensure the mathematical and financial correctness of calculation logic delivered, including edge cases and regulatory requirements
Collaborate with finance, compliance, and product teams to validate that supplier deliveries meet business intent
Support audit and regulatory reporting by ensuring calculation logic is transparent, traceable, and well‑documented
Investigate and resolve discrepancies in interest calculations, fee postings, or product behaviour, working with suppliers when needed
Define and execute test cases for financial calculation logic, including boundary and regression tests
Provide hands‑on internal support to other teams (finance, customer service, operations, and others) on questions about interest, fees, and product behaviour — this is a significant and ongoing part of the role

Qualifications and Experience

Desired Skills

4+ years of experience in a financial, analytical, or product role within financial services, lending, or payments
Strong understanding of interest calculation methodologies (e.g. effective interest rate, simple interest, compound interest, XIRR)
Experience writing detailed financial business rules and specifications for systems built by others
Solid grasp of product structures in consumer credit, BNPL, or instalment lending
Ability to work with complex financial specifications and verify that delivered systems implement them correctly

Nice to Have

Knowledge of Nordic or European consumer credit regulation (e.g. Consumer Credit Directive)
Experience with configuration‑driven financial product frameworks delivered by suppliers
Background in actuarial science, quantitative finance, or financial mathematics
Familiarity with accounting principles as they relate to interest and fee recognition

Behaviours

Exceptional analytical rigour — comfortable with mathematical precision and financial logic
Service‑minded and approachable — enjoys helping colleagues understand interest, fee, and product logic
Strong bridge‑builder between finance/business language and supplier requirements
Thorough documenter — understands that correctness must be explainable and auditable
Curious and proactive in challenging assumptions and validating requirements
Collaborative, with an ability to work effectively with business stakeholders and external suppliers